John was born April 16, 1942 in Wheaton, Minn., to Henry and Louise (Thoennes) Petermann. He was raised in Tintah, where he attended school. He married Dorothy Johnson on June 8, 1963, at St. Gall's Catholic Church in Tintah.

John began his farming career with Max Daniels and later Bob Ray. He worked and farmed with Leo and Richard Yaggie for 23 years. John owned and operated Petermann Pumping in Fergus Falls for six years. He returned to the farming industry that he loved so much and went to work for Kevin Yaggie in Brooks, Minn. Due to ill health in 1998, John retired from farming and returned to Breckenridge. In 2007, John and Dorothy moved to Detroit Lakes to be closer to their son Patrick and his family.

John enjoyed hunting, spending time with family and neighbors and playing with his grandchildren. John and Dorothy were long time members of St. Mary's Catholic Church in Breckenridge.